The present invention relates to braking of a vehicle, and in particular to a brake system of a vehicle.
Vehicles currently have brake systems that are used to inhibit rotation of the wheels of the vehicle to decelerate and stop the vehicle. The brake systems of the vehicles also have warning lights to notify nearby drivers that the driver of the vehicle is about to decelerate or stop the vehicle.
Heretofore, automotive braking systems are activated by the driver depressing a brake pedal. The onset of a driver""s intent to begin decelerating a vehicle, however, occurs prior to actually depressing the brake pedal. The elapsed time between these two events results in delayed warning of intent to following drivers via the warning lights and delayed braking of the vehicle (initiation delays). An additional form of delay (engagement delays) exists in the actual energizing of the warning lights and brake system from a totally dormant state to the fully active state. While these types of delay only last a fraction of a second, reducing these delays on this order of magnitude can mean significant improvement in stopping distance for both the braking vehicle and following vehicles, with the actual magnitude dependent on the vehiclesxe2x80x3 initial rate of travel. Stopping distance improvement can eliminate collisions or reduce the kinetic energy of a collision thereby improving safety of all involved and reducing property damage.
Some vehicles have included early warning light activation wherein the warning lights emit visible light before the vehicle is actually braking to indicate to following drivers that the driver of the vehicle is about to brake. However, early warning light activation can provide false positives wherein the driver actually does not have an intention to brake. Some traffic laws state that warning lights must indicate brake activation only when the brake systems are activated by the brake pedal. Furthermore, the lighting of warning lights when a vehicle does not brake can increase traffic congestion. Therefore, early warning light activation is undesirable.
Another alternative is to preheat the tungsten filament in a warning light continuously at a low voltage (below visible) coupled with a brief overvoltage at the time of application of the brake pedal. However, the continuously low voltage can reduce the life span of the warning lights.
Accordingly, a practical, economical braking system solving the aforementioned disadvantages and having the aforementioned advantages is desired.
An aspect of the present invention is to provide an early braking system for a vehicle comprising wheels, a braking system and a sensor. The braking system includes a friction element for inhibiting rotation of the wheels of the vehicle and a brake pedal adapted to be depressed to move the friction element into engagement with a portion of the wheels of the vehicle. The braking system has a dormant state wherein the friction element is at a first position spaced a first distance from the wheels. The sensor senses an operational parameter of the vehicle. The friction element moves from the first position to a second position spaced a second distance from the wheels in response to a predetermined measurement of the operational parameter and before depression of the brake pedal, wherein the second position is closer to the wheels than the first position.
Another aspect of the present invention is to provide an early brake warning system for a vehicle comprising a throttle for the vehicle, a sensor and a brake light. The sensor senses an operational parameter of the throttle. The brake light has a non-energized state wherein no energy is applied to the brake light, an energized state wherein a high energy is applied to the brake light such that the brake light emits visible light and a pre-energized state wherein a low energy is applied to the brake light whereby the brake light does not emit visible light. The brake light is energized from the non-energized state to the pre-energized state in response to a predetermined measurement of the operational parameter of the throttle.
Yet another aspect of the present invention is to provide a method of initiating braking for a vehicle having wheels. The method includes the steps of providing a braking system having a friction element for inhibiting rotation of the wheels of the vehicle. The braking system further includes a brake pedal adapted to be depressed to move the friction element into engagement with a portion of the wheels of the vehicle. The braking system also has a dormant state wherein the friction element is at a first position spaced a first distance from the wheels. The method further includes the step of sensing an operational parameter of the vehicle with a sensor. The method further includes the step of moving the friction element from the first position to a second position spaced a second distance from the wheels in response to a predetermined measurement of the operational parameter and before depression of the brake pedal, wherein the second position is closer to the wheels than the first position.
The early braking system and the early brake warning system are efficient in use, economical to install, capable of a long operable life, and particularly adapted for the proposed use.
These and other features, advantages, and objects of the present invention will be further understood and appreciated by those skilled in the art by reference to the following specification, claims and appended drawings.